The present invention relates to a process for the production of L-serine from glycine.
L-serine is one of amino acids well known in the art and is in a great demand as material for medicament.
Heretofore, L-serine has been prepared using various methods. For example, it has been obtained by hydrolysis of proteins.
As for processes for the production of L-serine from glycine by fermentation, process using a microorganism belonging to the genus Nocardia is known as described in Japanese Patent Publication No. 9391/76. However, the yield of L-serine is poor.
Heretofore, it is reported on page 80 of the summary of lectures in Congress of Fermentation Technology, Japan 1975, that the increased yields of L-serine are obtained by culturing a mutant belonging to the species Corynebacterium glycinophilum and having both the ability to convert glycine to L-serine and the lowered ability to decompose L-serine.
As other prior methods of producing L-serine by fermentation, processes of culturing a strain belonging to the genus Arthrobacter, Corynebacterium, Brevibacterium, Escherichia, Micrococcus, Pichia, or Candida in a nutrient medium or in a nutrient medium containing glycine are known.
However, processes which have a high yield of L-serine are in demand for utilization in industrial practice.
The present inventors have studied a process for producing L-serine from glycine. As a result, it has been found that improved yield of L-serine may be attained by contacting glycine with microbial cells of a mutant belonging to the genus Nocardia and capable of converting glycine to L-serine, in an aqueous medium.
Further, it has been found that more improved yield of L-serine may be attained by presenting an additive such as hydrocarbon, alcohol, etc. to the medium.
Furthermore, it has been found that in the culturing of the mutant in the nutrient medium containing glycine, increased yields of L-serine are obtained by presenting phosphate to the medium at a high concentration.